A startup, legally, is a business that is starting up. There is no requirement to actually incorporate or form a company as long as the intent to start a busin

A startup, legally, is a business that is starting up. There is no requirement to actually incorporate or form a company as long as the intent to start a business is present. The startup period is generally defined as a business's first year (possibly first two years) during which it is still engaged in the processing of beginning its business operations. Once it has begun its normal business operations, it is no longer a startup. A business with substantial revenue, traction, activities, _or_ funding, is legally by definition not a startup. It is simply a company. Twitter and Facebook are not startups, and they haven't been for years. Stripe is not a startup. Kickstarter is not a startup. BingoCardCreator is not a startup. But note that it is possible to have startups within an existing company. Tax-wise, at least, a business is distinct from a company. A business is a money-generating venture (or a venture intended to generate money); a company is a legal vehicle for housing one or more businesses. So long as the business activity is new, it may be a startup.